Which of the following will reach the earth in greater amounts if the number of chlorofluorocarbons released into the air increases?

Which of the following air pollutant is capable of preventing photosynthesis in plants?

One of the following does not contribute in producing acid rain. This one is:

The farmers use large amounts of a substance P in the fields to increase the crop yield. The excess of P dissolves in water and runs into a lake. The substance P causes rapid growth of tiny green water plants Q in the lake which cover the whole lake like a green sheet. When the plants Q die, the organisms called R decompose them by utilizing S dissolved in lake water. The amount of dissolved Sin water decreases too much due to which the fish living in lake suffocate and die. What are P, Q, R and S?

At many places the wastewater containing human excreta from homes and carried in big underground pipes is dumped into a river as such which pollutes the river water.

(a) What is the common name of such wastewater?

(b) Name five types of harmful organisms contained in it.

(c) Name any five human diseases caused by drinking river water contaminated with such wastewater.